In the U.S., sports fans must be talking about the top-seeded University of Virginia losing tonight to a 16 seed in the NCAA basketball tournament.

A No. 1 seed losing to a 16 had never happened, not in 135 previous encounters, until Virginia succumbed to the University of Maryland, Baltimore County (UMDC) by 20 points tonight.

Which came a few days after famed soccer coach Jose Mourinho, once self-described as “the Special One”, saw his globally famous Manchester United team lose, at home, to Seville, the fifth-best team in Spain, 2-1 — and getting knocked out of the Champions League in the round of 16.

What links those two games?

In each, the team expected to win is known for stressing defense over offense.

It has been a bad week for the notion that “defense wins games”, which suddenly seems in the eclipse across the sports world.

First, Mourinho and United.

They were 1-1 with Seville after the first leg, in Spain, when they looked like the better team. All they needed, before a packed, expectant throng at Old Trafford, was to win by a goal — or even in a scoreless draw.

But United, as has often been the case this season, played not to lose, a tactic which served Mourinho well on his climb in the coaching ranks, with Porto and Inter Milan.

It was while he coached the Italian club that he famously “parked the bus”, metaphorically speaking, in front of the goal in the second-leg match against Barcelona and Lionel Messi, playing with everyone committed to defense, securing a 3-2 aggregate victory — ahead of winning the 2010 Champions League final over Bayern Munich.

But that was eight years ago now, and Mourinho still seems committed to negation. When the opponent is a solid but not great Seville team, at home, and the Spanish side wins the leg 2-1 (and 3-2 on aggregate) … well fans will complain and critics will criticize, because United is an extravagantly wealthy club that boasts attacking players such as Paul Pogba, Alexis Sanchez, Willian, Romelu Lukaku and Marcus Rashford.

How could a defeat at the hands of Seville happen?

Much of the English media had a pretty good idea: It was about Mourinho’s devotion to defense even when United clearly had better talent than Seville.

Barney Ronay of The Guardian suggested Mourinho was “looking to attack an opponent’s strengths rather than its weaknesses, to win by nullifying space rather than using it to create. There is an element of the Peter Principle in this. Mourinho got so good at managing underdog teams and wringing the best out of B-list players he was allowed to manage overdog teams where his tactics no longer fit, with A-list players too good to carry out his methods with unquestioning zeal”.

Which led, a couple of days later, to Mourinho talking nonstop for 12 minutes about why his United team is really not all that good — when it has a dozen players any club in football would be happy to take.

Then, we have the University of Virginia, whose defeat was a far greater shock than United’s, given that it was unprecedented. And given that Virginia entered the game 31-2, fresh off setting a record for most victories in a season in the rugged Atlanta Coast Conference.

Virginia slugged its way through the season by keeping other teams from scoring — opponents averaged a puny 53 points per game.

UMBC entered the NCAA tournament with a 24-10 record, having lost to sub-mid-major schools like Stony Brook, Colgate, Army, Towson and Albany (in an 83-39 rout two months ago).

True story: When I saw “UMBC” on the TV coverage, I had no idea what those letters stood for. And even after nine years out of the states, I can ID 99 percent of schools in the tournament by their initials.

The Retrievers (perhaps the least-dignified of all college “dog nicknames”) made the tournament thanks to a buzzer-beating shot over nemesis Vermont in the tourney final of the little-known America East Conference.

Then they played Virginia to a 21-21 draw at intermission before breaking open the game with a hail of three-point shots to win with ease, 74-54 — outscoring Virginia 53-33 in the second half. UMBC pretty much won the game beyond the arc, in the progressive fashion, making 12-of-24 threes to Virginia’s grim 4-for-22 and scoring all but one of their goals beyond the arc or in the paint.

The U.S. being the home of stat-wonkery, all sorts of people got involved in the “how could this happen” discussion … when it had not happened since the NCAA tourney went to 64 teams (and four regionals of 16 teams) in 1987 — 33 seasons ago.

It was suggested in the New York Times that low-scoring games are fraught for elite teams because they arrive at the game with better players, and allowing the game to hinge on a handful of possessions is dangerous.

Virginia’s defense-first-second-and-third preference, which includes a markedly ultra-slow approach to games, could explain Virginia’s spotty tournament record under coach Tony Bennett.

“Because of the way they play, as great as it is — I love the way they play — there is a chance for a smaller margin of error,” Seth Greenberg, an ESPN analyst who went 3-3 against Bennett’s teams while coaching Virginia Tech, told The Times.

Virginia may be slightly more likely, said Greenberg, “to pick a bad day to have a bad day”.

Per NYT: “Playing slowly leaves better teams more vulnerable to upsets, John Harris, a mathematics professor at Furman University who, with two other faculty members, has studied NCAA tournament upsets. He groups teams into ‘Giants’ and ‘Killers.’ The Giants are always the better team. The variable is what improves the underdogs’ chances. The answer, it turns out, is when the Giants’ giant-like qualities are minimized, because a slow pace means there is literally less basketball being played.

“Picture it in terms of an extreme case,” Harris told The Times. “If each team had one possession, a Killer is more likely to upset a Giant. The more possessions you give a Giant, the more likely it is they’re able to separate.”

And there went the Cavaliers, perhaps even more red-faced than they were in 1982, the last year in which they were top-ranked in the nation — and lost to tiny Chaminade of Hawaii 77-72, in Honolulu, a couple of days before Christmas. It was an upset so ridiculous I remember putting in the front page of our sports section.

Looking around the sports world … baseball seems to be reversing several seasons of declining offense … in the NFL, no one plans to hold an opponent to less than two touchdowns … in the NBA, the emphasis on the three-point shot has boosted scores and changed the game.

In soccer, it is the brave and the bold and the attacking teams, such as the Manchester City club of Pep Guardiola, Mourinho’s arch-rival, that win the biggest trophies.

Not only is a defensive attitude an invitation to failure against lesser opponents, it also is more likely to enrage fans. The worst of both worlds, where Mourinho and Virginia’s Bennett find themselves.

Most fans would say that if their team is going to lose, they would like it to go out in a blaze of glory, on the attack, and not cowering in defense. Counting on negating the opposition instead of dominating it.